Water-Triggered Ductile-Brittle Transition of Anisotropic Lamellar Hydrogels and Effect of Confinement on Polymer Dynamics

作者：Ilyas Muhammad; Haque Md Anamul; Yue Youfeng; Kurokawa Takayuki; Nakajima Tasuku; Nonoyama Takayuki; Gong Jian Ping^*

来源：Macromolecules, 2017, 50(20): 8169-8177.

DOI：10.1021/acs.macromol.7b01438

We study the effect of dehydration On the structure and mechanical properties of anisotropic lamellar hydrogels, consisting of alternative stacking of several thousands of nanoscale rigid bilayers from amphiphilic poly(dodecyl glyceryl itaconate) (PDGI) and submicroscale soft hydrogel layers from hydrophilic polyacrylamide (PAAm) networks. We found that the layered microstructure is well preserved with dehydration, and a ductile-brittle transition occurs at the critical water-content. This, transition is related to the rubbery-glassy transition of the PAAm layers, which occurs at 58 wt % water content and is much higher than 26 wt% of bulk PAAm hydrogels. Such specific behavior of the lamellar hydrogels indicates that the dynamics of the submicroscale PAAm hydrated layer intercalated between the rigid bilayers are very different from its bulk state.

• 出版日期2017-10-24